From The Cincinnati Drug & Poison Information Center

Summer heat and sun may potentially put some medication users and alcohol and/or drug abusers at increased risk. The following describes reactions that may occur in some patients receiving certain mediations. Don’t stop taking prescribed medicine without first talking to your doctor.

THE HEAT The body needs to maintain a relatively consistent temperature to function correctly. When exposed to elevated temperatures, the body keeps from overheating through several ways. Increasing blood flow to the skin helps the body lose heat. Sweating also allows the body to release heat. Physical activity, fluid intake, type of clothing and the temperature of your surroundings will affect your body’s ability to maintain a safe temperature. To increase blood flow to the skin, the body informs the brain of an elevated temperature. The brain responds by sending a message to blood vessels to increase blood flow to the skin. The heart also responds by working harder to circulate the blood. Some medications may inhibit the body’s ability to increase blood flow to the skin.

Certain psychiatric medications (including haloperidol) and alpha-blockers (including terazosin) may block the body’s message to the brain regarding the elevated temperature. Stimulants and decongestants actually reduce blood flow to the skin Water pills, alcoholic beverages and products containing caffeine may cause dehydration. Certain blood Pressure medications

Sweating is an important way the body stays cool. Some medications may reduce sweating.

Tricyclic antidepressants (including amitriptyline, Nortriptyline). Cold and allergy medications ( including diphenhydramine, tripolidine, chlorpheniramine). Drugs of abuse (including Jimson Weed, PCP)

In response to increased temperature, one may move to a cooler area or lighten clothing. Some medications may cloud judgment and impair the ability to realize the need to act.

Sedatives (including alcoholic beverages, diazepam, alprazolam) Opioids (including hydrocodone, morphine, codeine)

If you are taking any of these medications, be aware that your ability to deal with the heat may be impaired. Even if you are not taking any medications, it is a good idea to wear lightweight clothing, drink plenty of fluids, stay in the shade and avoid heavy activity. Overheating can be a medical emergency. Symptoms of heat exhaustion may include weakness, anxiety, fatigue, thirst, dizziness, headache, anorexia, nausea, vomiting, agitation, impaired judgment and faintness, which may lead to collapse. If left untreated, the condition may lead to heat stroke. Symptoms of heat stroke may include headache, slurred speech, dizziness, faintness, hallucinations, seizures, confusion, delirium or coma. If you suspect that you are overheating, contact your doctor or pharmacist right away.

THE SUN Some medications may cause patients to burn more easily. The reaction is known as photosensitivity. The most common form of photosensitivity is a phototoxic reaction. A phototoxic reaction usually involves redness and tenderness of the skin and generally occurs 2 to 6 hours after exposure to ultraviolet A (a type of sunlight). The reaction may be as severe as blistering. A less common form of photosensitivity is a photoallergic reaction. A photoallergic reaction usually involves itching and scaling of the skin, and this generally occurs 5 to 10 days after exposure to ultraviolet A. The reaction may be severe. The following are some of the herbs and medications that may potentially cause a photosensitivity reaction: acetazolamide, acetohexamide, alprazolam, amantadine, amiodarone, amitriptyline, amobarbital, amoxapine, azithromycin, benzocaine, butabarbital, captopril, carbamazepine, celecoxib, carbinoxamine, Chlordiazepoxide, chlorhexidine, chloroquine, chlorothiazide, chlorpromazine, chlorpropamine, chlorhexidine, chloroquine, chlorothiazide, chlorpromazine, chlorpropamine, chlorthalidone, ciprofloxacin, clozapine, co-trimoxazole, cyproheptadine, dacarbazine, dantrolene, dapsone, demeclocycline, desipramine, dichlorphenamide, diflunisal, diphenhydramine, divalproex sodium, doxepin, doxycycline, estrogen/progestin, felbamate, fenofibrate, fleroxacin, floxurifine, flucytosine, fluorouracil, fluphenazine, fluvoxamine, furosemide, ganciclovir, blipizide, glyburide, griseofulvin, haloperidol, hy